Six people may have contracted coronavirus after voting in the Wisconsin presidential primary election which was held amid the pandemic.
Health officials in the state said a seventh person – a poll worker – were infected with Covid-19 in Milwaukee.
The vote was held on April 7 despite widespread concern about the public health risk brought about by coronavirus.
Difficulties in finding poll workers forced the city to reduce the number of polling locations from nearly 200 to just five, and where voters – some in masks, some with no protection – were forced to wait in long lines for hours.
It is not certain that the seven people contracted the virus at the polls, and the possible connection was made because local health officials are now asking newly infected people whether they participated in the election.
“It means they were at the polls, which is a potential exposure, but (we) can’t say they definitely got it at the polls,” said Darren Rauch, the health officer and director for suburban Greenfield, and one of the health officials helping with the coronavirus response in the Milwaukee area.
Officials are still gathering information from about 70% of people who have tested positive since the election and hope to have a full report later this week, city health commissioner Jeanette Kowalik said.
The election, which included a presidential primary as well as a state Supreme Court race and local offices, took place after a legal struggle between Democrats and Republicans.
A day before the election, Democratic Governor Tony Evers ordered that it be delayed and shifted to postal voting, only to be overturned when Republican legislative leaders won an appeal in the state’s conservative-controlled Supreme Court.
Thousands of Wisconsin voters stayed home, unwilling to risk their health and unable to be counted because requested absentee ballots never arrived.
State health officials had warned of an expected increase in infections from the election.
Wisconsin’s election has been a flashpoint of contention as Democrats and Republicans grapple with how to conduct elections in the coronavirus era as the November presidential race approaches.
Democrats and voting rights groups have filed lawsuits to expand mail and absentee voting options, and pushed for an extra 2 billion dollars (£1.6 billion) to help states adjust their election systems.
National Republicans are fighting those efforts, while President Donald Trump claims without evidence that postal voting is vulnerable to fraud.